Recommended Citation

NOTE: At the time of publication, the author David Headrick was not yet affiliated with Cal Poly.

Abstract

Tephritis baccharis (Coquillett) is bivoltine and monophagous on Baccharis salicifolia(Ruiz & Pavon) Persoon in southern California. The egg, the second and third instar larvae, and puparium are described and illustrated. Eggs are inserted singly into terminal buds of main and axillary branches in late winter or early spring. First instar larvae hatch and tunnel into the pith just basad to the apical bud where they initiate gall formation. Gall and larval growth continue slowly into the fall, when pupation occurs. Most F1 flies emerge, mate, and after about one week begin oviposition. Some F1 flies that emerge in the fall may overwinter as adults; however, a few F1 individuals may not emerge and instead overwinter as pupae in puparia in mature galls. Second and third instar, F2 larvae also overwinter in developing galls. Flies were long-lived under laboratory conditions; males and females lived an average of 140 days and 83 days, respectively. This longevity and the long fecundity period of females allow T. baccharis to attack the new buds and branch growth produced by B. salicifolia, because this phraetophyte is capable of protracted, nearly year-round vegetative growth and flowering in southern California.